Standard Test Method for Breaking Strength and Elongation of Textile Fabrics (Grab Test)

 

Theory:

 

The Grab Test for textiles is the most popular textile tensile test. The material is gripped in the middle, with a measured amount of material hanging out of the ends. There are two types of test samples, and one involves fraying the ends of the sample that are not gripped. Basic testing for textiles requires a Controlled Rate of Extension (CRE) machine. 

Industry:

This procedure is relatively simple however many manufacturers use it as the backbone of their quality and R&D initiatives. The sector hit an all time low in 2010 from a combination of the housing crisis as well as offshoring directives. Since then it has returned to growth and in 2015 the US textile industry, including apparel, is poised to produce over $75 billion in product.  Fabric and textile output correlates very highly to the housing industry, as more houses means more closets to store clothes in and more furniture to upholster. The macro-economic trends of automation and low energy prices in the US bodes well for future gains for the textile manufacturing sector.

Solution:

Vise Grips are the simplest solution for this test. There are many types of grip faces that are available including flat metal, rubber, serrated, and wave. Textile tests are usually run in quick sequences and therefore it is absolutely worthwhile to use pneumatic grips if the machine gets regular use.

 

Analysis:

The calculations for ASTM D5034 include the breaking force which is the average force required to pull apart the sample. The average is taken from multiple samples tested under similar conditions. Other numerical values than can be gleaned from this test are Elongation at break, Peak Load, and Load at Extension point.